In the natural science museum, we can see biological fossils from different geological and historical periods, most of which are biological remains, which are formed by the parts left behind after the death of animals and plants, usually hard parts, such as dinosaur bones, trilobites carapaces, nautilus shells, etc., but in some cases, the formation of fossils is not always accompanied by the death of organisms.
While living, living organisms are able to influence their surroundings, even if it is only an accidental act. As we are all familiar with the phrase "unintentional willow shade", if the organism continues to be active in a fixed environment for a long time, it will cause greater changes or destruction, such as benthic organisms feeding, moving, and excreting in the sedimentary environment, which will churn, mix and destroy the surrounding sedimentary particles, and over time, these behaviors even form or structure that are obviously different from the original sedimentary environment, which is the biological disturbance action, and those forms or structures may form fossils in a long geological history period , called a fossil remains.
Grinding stone
Unlike fossil remains, fossil remains can be produced by any organism, whether it has a hard body part or not, and different organisms of similar body shape and behavior patterns can form the same fossil remains, while organisms of the same species, due to differences in individual body size and behavior patterns, will form different fossil ruins, even if the same organism, in different sedimentary environments (such as sandy soil with different degrees of softness) can form different fossil ruins.
Bifolium
Therefore, if the remains of the fossil preservation is the appearance and physiological structure of the organism, then the relic fossil preservation, is the behavior and habits of the organism, according to the habit, the relic fossils can be classified as living traces, crawling traces, resting traces, foraging traces, eating traces, escape traces, etc., manifested in the geological structure, is a variety of submerged holes, drill holes, biological erosion structures, etc., they are not only the evidence of the existence of paleontology in some special sedimentary environments, more importantly, they can allow us to obtain some information that cannot be seen from the remains of the stone. For example, a footprint fossil can provide us with a lot of information about what the owner of the footprint is, in what direction it is moving, whether it is walking or running, whether it is voluntary or forced to go, and at the same time, it can also provide information about the environment of the rock formation at the time when they are found, such as salinity, sedimentation, oxygen content, etc.
Dinosaur footprint fossils
The preservation of relic fossils in the rock layer, but also to reveal the cause, time, location and other information of the formation of fossils has a very important role, preserved in the surface of the rock formation of the fossil remains are called upper relief, preserved in the interior is called full relief, and preserved in the bottom surface is called the lower relief, although it is difficult to identify and classify the organisms that produce the fossils, but it can provide important information such as the sedimentary environment and the interspecific relationship between the organisms in it.
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Some of the images originate from the Internet